April 16
Veil Nebula
Observed in 2015
In this small piece of the Veil Nebula, wisps of gas are part of what remains of a star that was once 20 times more massive than our Sun. A fast-moving blast wave from the star's explosion is plowing into a wall of interstellar gas, causing it to glow.
Image credit: NASA, ESA, Hubble Space Telescope